1. Technical Field
This application relates to a handling machine for containers such as bottles, cans etc., for example of a bottling machine for bottling liquids in bottles with filler valves located on a rotor and lifting devices associated with the filling valves to lift the bottles toward the discharge openings, whereby the lifting devices are realized in the form of lifting rods that can be moved vertically against a spring force with holding devices located in the lower area in the form of grippers, support and centering surfaces for the container mouth and/or the neck collar of the container.
2. Background Information
In particular during the bottling of beverages such as mineral water, beer or other carbonated beverages, for example, under counterpressure, lifting devices are used, the lifting cylinders of which are realized with bottom or support plates. The bottles standing vertically on these plates, optionally with the use of corresponding centering grooves, are lifted toward the discharge openings of the filler valves, lowered after the filling process has been completed, removed from the filling machine and transported to a capping machine.
Because the beverage is under pressure, to prevent excessive foaming, a corresponding counterpressure must be established in the bottles to be filled. For this purpose, before the actual filling process, and optionally with the inclusion of additional measures such as pre-evacuation, flushing with a sterilization medium, etc., the bottles are pre-pressurized with the pressure prevailing in the bottling machine boiler, using the carbon dioxide in the boiler.
Designs of the prior art have pressing devices which are engaged in an appropriate manner with the container—for example a plate that engages the bottom of the container—to press the container against the filling mechanism as necessary. In the designs of the prior art, the pressure force is applied by compression piston devices which are located underneath the bottle plate, for example, or can be suspended on the filling mechanism. What the constructions of the prior art have in common is the pressurization of the compression piston arrangement with a compressed gas from a separate compressed gas source, which has an adjustable constant pressure during the working stroke. The application force is thus constant during the operation of the filling mechanism. In the designs of the prior art, the compression piston arrangements are pressurized constantly, and therefore operate according to the principle of a pneumatic spring. The application device is lowered and raised against the piston pressure by means of guide cams or similar mechanisms. For safety reasons, the application force is set high enough by a suitable selection of the pressure of the compressed gas that pressurizes the pressure piston arrangements so that there is always sufficient pressure for all the beverages being bottled in the plant, which can have different levels of carbonization pressures, to prevent foaming or the escape of gas or fluid on the edge of the container. This method has the disadvantage, however, that the pressure force is generally too high, i.e. higher than necessary. However, the level of the pressure force affects the wear of parts at various points on the filling device, such as, for example, the gaskets or the components of the bottle pressing device. Therefore a sealing force that is too high is a disadvantage. It is also obvious that a significant pressure is also exerted on the bottles themselves when they are pressed against the filler valves. Such a pressure seldom or only rarely has any corresponding disadvantages when it is exerted on glass bottles, but that is not the case with plastic bottles, which are being used to an increasing extent, and on which the clamping pressure between the filling valves and the bottom support plates causes an unacceptable and undesirable deformation of the cylindrical portion of the bottle. To prevent this problem, lifting devices are used that have grippers located on support rods or support surfaces that come into contact with the neck collars located in the mouth area of plastic bottles or other commonly used containers. A filling machine of this type is known from publications in the prior art. The support rods are thereby located with the corresponding support surface as an independent component with a cam roller underneath the outlet of the filler valves.